text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2015 Damien P. George
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include <string.h>
  #include "py/mphal.h"
  #include "board.h"
  
  static int interrupt_char;
  
  void mp_hal_init(void) {
      MP_STATE_PORT(keyboard_interrupt_obj) = mp_obj_new_exception(&mp_type_KeyboardInterrupt);
  }
  
  mp_uint_t mp_hal_ticks_ms(void) {
      // TODO
      return 0;
  }
  
  void mp_hal_delay_ms(mp_uint_t ms) {
      // tuned for fixed CPU frequency
      for (int i = ms; i > 0; i--) {
          for (volatile int j = 0; j < 5000; j++) {
          }
      }
  }
  
  void mp_hal_set_interrupt_char(int c) {
      interrupt_char = c;
  }
  
  int mp_hal_stdin_rx_chr(void) {
      for (;;) {
          if (uart_rx_any()) {
              return uart_rx_char();
          }
      }
  }
  
  void mp_hal_stdout_tx_str(const char *str) {
      mp_hal_stdout_tx_strn(str, strlen(str));
  }
  
  void mp_hal_stdout_tx_strn(const char *str, size_t len) {
      for (; len > 0; --len) {
          uart_tx_char(*str++);
      }
  }
  
  void mp_hal_stdout_tx_strn_cooked(const char *str, size_t len) {
      for (; len > 0; --len) {
          if (*str == '\n') {
              uart_tx_char('\r');
          }
          uart_tx_char(*str++);
      }
  }
  